A woman who claims she was duped into assassinating Kim Jong-un's brother wept in court as her lawyer disputed claims the victim was poisoned with VX nerve gas.

Indonesian Siti Aisyah and Vietnamese Doan Thi Huong, who are accused of fatally smearing Kim Jong-nam's face with banned nerve agent at a crowded airport terminal in Kuala Lumpur on February 13, appeared in front of High Court Judge Azmi Ariffin who set October 2 as the trial date.

The women face a possible death penalty if convicted and say they were tricked into thinking they were playing a harmless prank for a hidden-camera TV show.

Analysing evidence on Friday, Gooi Soon Seng, Aisyah's lawyer, told reporters that 'traces of precursors of VX and degrading products of VX' were found on Kim's face and the women's clothing based on government documents, saying the substance needed to be scrutinised.

Prosecutor Muhamad Iskandar Ahmad said he plans to call up to 40 witnesses, including 10 experts and a few foreigners.

The women appeared in court wearing traditional Malay dresses, smiling at their lawyers and embassy officials. They were handcuffed as they were led to the dock.

But after the judge left the room, Aisyah was in tears as her lawyer debriefed her.

The two women are the only suspects in custody in a killing that South Korea's spy agency said was part of a five-year plot by North Korean leader Kim Jong Un to kill a brother he reportedly never met.

Malaysian police have said four North Korean suspects fled the country the same day Kim Jong Nam was killed.

General Operations Force policemen arrive to provide security during the court appearance of Indonesian national Aisyah and Vietnamese national Doan Thi Huong at the Shah Alam High Court in Shah Alam, outside Kuala Lumpur on June 28, 2017, for their alleged role in the assassination of Kim Jong-nam, the half-brother of North Korean leader Kim Jong-un

Earlier, prosecutors provided airport camera footage to the defense.

Gooi said it included a video of a prank played by Aisyah on someone else at the airport.

He didn't give further details.

North Korea has a history of ordering killings of people it views as threats to its regime.

While Kim Jong Nam was not thought to be seeking influence, his status as eldest son in the current generation of North Korea's founding family could have made him appear to be a danger to his half brother's rule.

Pyongyang has denied any role in the killing and has not even acknowledged that the dead man was Kim Jong Nam.